Background: Periodontitis is one of the major reasons for tooth loss in adults. India, with a population of over 1 billion, is bound to become a developed nation soon. This transition will require a population that is healthy, including in terms of periodontal health. Early studies done in India gave an indication that the population is highly susceptible to periodontitis. Aim: This paper reviews the prevalence of periodontitis in the Indian population. Settings and Design: Review of periodontitis prevalence studies on the Indian population. Materials and Methods: After identifying articles from PubMed and hand searching, the epidemiology of periodontitis is reviewed together with the case definition, study settings, type of population, age and other factors as all these are bound to affect the prevalence rates determined in various studies. Statistical Analysis: None. Results: This review identifies very limited number of studies that provide prevalence data and faces difficulty in comparing various studies due to nonstandardization of case definition and use of nonrepresentative samples. There is a high prevalence of periodontitis among the adults and the economically weak population. Conclusions: There is a very urgent need for standardized population-based studies with a robust design to identify the true prevalence of periodontitis, which in turn will help in planning oral health policies and creating the necessary infrastructure.

India is one of the major emerging market economies with a population of over 1 billion and - is very diverse in geography, culture, tradition, habits and even race. This diversity also extends to literacy rates, health indicator rates infant mortality rate (IMR) and hygiene practices. This variation is reflected in the periodontitis prevalence as is revealed by the two major surveys conducted. [1],[2]

There has been a general perception that oral health in India is considered to be the least important. In India, [1] the dental-care scenario is unique. At present, there are more than 267 dental colleges, producing approximately 19,000 dental graduates per year and almost 3,000 specialists. The dental colleges offer excellent tertiary care, in a cost-effective manner. India is becoming a favored tourist destination for orodental treatment of international standards. On the other hand, even the most basic oral health education and simple interventions like pain relief and emergency care for acute infection and trauma are not available to the vast majority of population, especially in the rural areas. One of the reasons is lack of epidemiological data to identify areas needing oral health care. There also prevails a view that people in Asia are particularly susceptible to periodontitis. This view of a particularly high prevalence of periodontal diseases appears to have originated from early epidemiological studies using an index system that gave weight to gingivitis and moderate periodontitis resulting from poor oral hygiene and calculus deposition. [3] Albandar [4] in an overview concluded that subjects of Asian ethnicity had the third highest prevalence of periodontitis.

The aim of this review is to determine the prevalence of periodontitis in India.

Materials and Methods

Using keywords "Periodontitis" and "India", "Periodontal" and "India", PubMed was searched for articles. Out of the 163 articles found, all articles that included prevalence studies were selected. As very few prevalence studies have been done in the representative Indian population, all available studies in which prevalence data was available were considered regardless of any other inclusion criteria. Some articles from Indian journals that had prevalence data on periodontitis but were not indexed by PubMed were also selected. Totally 14 publications, which included 2 national surveys, were included [Table 1].

Table 1: Prevalence data of periodontitis from various studies done on the Indian population

To begin with, this review will consider 2 important surveys - one by Dental Council of India and the other by Government of India in collaboration with WHO. Early "classic" periodontal epidemiological studies in India are also reviewed to understand why India was considered to be a region of periodontitis endemicity. In this review, moderate periodontitis is considered to be present if a person has at least one site with a probing depth of ≥4 mm; and severe periodontitis, at least one site with a probing depth of ≥6 mm.

National Oral Health Survey and Fluoride Mapping (2002-2003), Dental Council of India, New Delhi, 2004

This is the first ever national-level epidemiological survey done in India. The aim of the survey was to collect information covering various dimensions of oral health, including prevalence of oral health problems. Each state was divided into a few homogeneous regions comprising of a number of districts, on the basis of agro-climatic factors used by the Planning Commission. A three-stage sampling design was adopted to select 210 rural and 110 urban subjects in each of the age groups, viz., 5, 12, 15, 35-44, 65-74 years, from each homogeneous region. WHO probe was used for periodontal measures, and CPI index was used for disease assessment. The prevalence of periodontal disease increased with age. The prevalence was 57%, 67.7%, 89.6% and 79.9% in the age groups 12, 15, 35-44 and 65-74 years, respectively (periodontal disease is not evaluated in 5 year olds). The lower prevalence in older age could be due to loss of teeth in the elderly. Moderate periodontitis was seen in 17.5% of the 35-44 years group; and 21.4%, in the 65-74 years group; whereas severe disease, defined as at least one tooth with ≥6 mm probing depth, was seen in 7.8% in the 35-44 years group and 18.1% in the 65-74 years group. No marked gender differentials were observed, and marginally higher prevalence was seen in rural subjects. "Cleaning teeth regularly" group showed significantly reduced prevalence of periodontal disease, while use of toothbrush was found to be significantly better than finger cleaning. The survey was basically a prevalence survey with less emphasis on risk factors. This survey gave a reliable baseline data at the national and state levels.

Oral health in India

A report of the multicentric study, carried out under the Directorate General of Health Services, Ministry of Health and Family Welfare, Government of India; and World Health Organization collaborative program.

Under the Government of India and World Health Organization collaborative program on oral health, a multicentric oral health survey was envisaged in the year 2004, in order to have a baseline data of the burden of oral diseases and associated risk profile of the population for four index age groups, viz., 12, 15, 35-44 and 65-74 years. This survey was conducted in 7 different geographical locations in India, viz., Arunachal Pradesh, Delhi, Maharashtra, Puducherry, Rajasthan, Orissa and Uttar Pradesh, covering 3,200 samples from each site, thus surveying a total of 22,400 persons in rural and urban areas of the selected districts. In the 35-44 years and 65-74 years age groups, high prevalence (100%) of periodontal disease was reported from few of the states (Orissa, Rajasthan) in this study. The prevalence of loss of attachment (3 mm or more) was 78% in the 35-44 years group and 96% in 65-74 years group in Maharashtra in the present study. The prevalence of attachment loss of >3 mm in the 35-44 years group was highest in Maharashtra (78%), followed by Orissa (68%) and Delhi (46%). The rest of the centers had prevalence ranging between 15% and 33%. The prevalence of loss of attachment was significantly higher in the 65-74 years group as compared to the 35-44 years group. The highest prevalence in 65-74 years group was recorded in Maharashtra (96%), followed by Orissa (90%), Delhi (85.5%), Rajasthan (75%), Uttar Pradesh (68%) and Puducherry (55%). Arunachal Pradesh recorded the lowest prevalence, viz., 20%. The general trend observed for loss of attachment was that it was higher in the rural than in the urban population and was higher in males as compared to females. But in the geriatric age group, the prevalence of loss of attachment was higher among females.

Shah [5] in her report for the National Commission on Macroeconomics observed that more advanced periodontal disease with pocket formation and bone loss, which could ultimately lead to tooth loss if not treated properly, may affect 40% to 45% of the population of India. She also pointed out that only some 7 studies were documented and highlighted totally incoherent data. Moreover, most of the studies have been conducted on the pediatric population, in whom periodontal diseases are not widely prevalent.

Sood [6] in a field survey in Ludhiana did a systematic sampling on 500 urban and 500 rural subjects. In the total population, 68.9% had bleeding gums, 97.0% had calculus, 29.1% had shallow pockets (moderate periodontitis) and 12.5% had deep pockets (≥6 mm, severe periodontitis) as assessed by WHO-recommended methods. He found periodontal disease significantly associated with coronary artery disease (CAD); however, the sample size was small in the CAD group (34 subjects).

Singh et al.[7] did a prevalence study in the rural and urban subjects of Ludhiana. He found that the urban subjects had higher prevalence of moderate and severe periodontitis as compared to rural subjects.

Jagadeesan et al.[8] did a systematic random sampling of rural women in Puducherry. The prevalence of moderate periodontitis increased with age; the risk of being affected by periodontitis was 2.3 times for persons above 35 years of age than below.

Doifode et al.[9] in a field survey of two randomly selected nagars of Nagpur found prevalence of periodontal disease being 34.8%. The disease definition was not given; hence the level of periodontitis could not be ascertained. Age, low socioeconomic status, betel nut/leaf chewing, tobacco chewing, ghutka chewing and smoking were significantly associated with periodontal disease.

Vandana et al.[10] found 27% prevalence of periodontitis in fluorosis-affected patients attending Periodontics OPD. Prevalence increased with age and was significantly more among females. The prevalence should be considered keeping in mind that the population was a hospital-based one. The increased prevalence found among females could be attributed to their increased treatment-seeking behavior.

"Classic" periodontal epidemiological studies in India

The study by Greene [11] is one of the earliest studies. It used Russell index for periodontitis. The periodontal index (Russell, 1956) includes both gingival inflammation and periodontal destruction, with weight given to marked gingival inflammation, which makes reversible marked inflammation equivalent to irreversible periodontal destruction in the calculation of the index. The study surveyed young persons aged 11 to 17 years comparing urban and rural persons and also a seperatesmall sample of 69 persons aged 18 to 30 years. The population was selected from schools of low socioeconomic status. Ninety-seven per cent of the 11- to 17-year-old persons examined had overt evidence of periodontal disease, while fewer than 2% of the total had obvious periodontal pockets. All the 63 persons over 17 years of age had overt gingival inflammation, and 19 (30.2%) had obvious periodontal pockets. Persons with obvious periodontal pockets (periodontitis) constituted 0.2%, 0.4%, 1% and 6% in the 11, 13 15 and 17 age groups, respectively.

Ramfjord et al.[12] in their paper discuss a WHO survey done in India along with 4 other countries. They observed that there was 100% prevalence of periodontal disease (including gingivitis) in India. Periodontitis was found to start after age 15; and at 17 years, 10% of Indian boys had periodontitis. This periodontitis was due to accumulation of calculus, plaque and debris rather than due to age, sex, geography, economic status or nutrition.

Sanjana et al.[13] did a study on Bombay residents in 1956 and found 83.2% had signs of periodontal disease. As prevalence of pockets was not specified separately, the true prevalence of periodontitis could not be ascertained. The population seemed to belong to low socioeconomic strata, with age being a risk factor.

Other studies

Ranganathan et al.[14] compared the prevalence of periodontitis in HIV seropositive and seronegative patients in Chennai. The controls were dental patients attending the OPD of a dental college. The prevalence was high at 86% when assessed by Community Periodontal Index for Treatment Needs (CPITN). The lower threshold of at least one site with probing depth ≥3 mm and the population being patients seeking dental care could be the reasons for the high prevalence. Periodontitis was seen in 92.7% of HIV patients, which if compared with prevalence in the general population is extraordinarily high.

Ranganathan et al.[15] report the prevalence of periodontitis in 1,000 HIV-positive patients; 22.6% females and 36.3% males had periodontitis, with an odds ratio of 1.96. None of females examined were smokers, while 50% of males examined were smokers. Smoking and increased age were important reasons for increased prevalence of periodontitis among males.

Parmar et al.[16] compared chewers of areca nut with or without tobacco with non-chewers in a hospital-based population and found 22.6% of chewers were smokers and the chewers had a prevalence of periodontitis of 54.76%, while the controls had a prevalence of 31%. The quid chewers were at higher risk for periodontitis and gingival recession, irrespective of sex, age and smoking status.

Rooban et al.[17] compared drug abusers with controls from a dental hospital. They found there was a higher prevalence of periodontitis among controls despite the number of smokers being significantly high among drug abusers. This may be probably as a result of selection bias; dental disease would obviously be more prevalent among dental hospital patients.

Discussion

The populations mostly studied have been hospital-based populations because of the convenience (convenient sample). The prevalence assessed among these types of samples will be higher than that assessed among the general population as persons with dental problems attend hospitals, and they are not representative of the general population. The prevalence in the hospital-based population is about 10% higher as compared to that in the general population. The early studies [11],[12] were done on school population, another popular and convenient sample. The school population represents a young population, and only those who can afford to attend schools will be represented; and the school population is the least representative of the periodontitis-susceptible population. However, if young persons show levels of periodontitis as seen in the Ramfjord et al,[12] surveys, it is a cause for alarm as it reflects a poor hygiene status and dental service utilization by the population.

Another limitation observed was the use of CPITN as a case definition for periodontitis. CPITN is a treatment need-based index, meant to find out the prevalence of persons requiring treatment. It does not give true prevalence rates in terms of severity and extent. A person with a site of >10 mm will be in the same scale as a person with a single site of 6 mm (Code 4). The partial recording will give an underestimation of prevalence.

Further, the prevalence data should correlate with tooth loss to find if the increased prevalence of periodontitis is reflected in increased tooth mortality. This will also help us find at what level of severity of periodontitis is tooth loss a consequence. Abnormal probing depth is a cause for concern if it leads to increased risk for tooth loss, and its threshold should be identified based on its consequence. Yet very little data are available on tooth loss. [5]

In the World Oral Health Report (2003), [18] the WHO Global Oral Health Program formulated the policies and the necessary actions for the improvement of oral health. The strategy is that oral disease prevention and the promotion of oral health need to be integrated with chronic disease prevention and general health promotion as the risks to health are linked (like tobacco consumption and the standard of hygiene). As for the major chronic diseases, socio-environmental factors are indirect causes of oral disease; moreover, a core group of modifiable risk factors is common to many chronic diseases and injuries, as well as most oral diseases. These common risk factors are, however, preventable as they relate to life style - such as dietary habits, use of tobacco and excessive consumption of alcohol - and the standard of hygiene. Yet for effective integration of oral disease management with management of other chronic diseases, prevalence data along with risk due to various factors should be available. Oral disease, including periodontal disease and tooth loss, is a serious public health problem. Its impact on individuals and communities in terms of pain and suffering, impairment of function and reduced quality of life is considerable. With the growing consumption of tobacco in many low- and middle-income countries, the risk of periodontal disease, tooth loss and oral-cavity cancer is likely to increase. Moreover, periodontal disease and tooth loss are linked to chronic diseases such as diabetes mellitus; the growing incidence of diabetes in several countries may therefore have a negative impact on oral health. Yet to formulate policies, the true prevalence of periodontitis, which affects economy and the quality of life, needs to be assessed. Theoretically and in most studies, abnormal loss of attachment has been regarded as periodontitis; this definition is not useful as most persons above 35 years of age have at least one site ≥3 mm. The definition of at least one site ≥6 mm can be regarded as useful for population-based assessment of prevalence. Let us also remember that this threshold of 6 mm is not based on studies on Indian population. We also should strive to find the definition of destructive periodontitis suitable for the diverse Indian population.

Shah [5] in her report for the National Commission on Macroeconomics and Health (NCMH) observed that for periodontal diseases, the projection is alarming, with prevalence at present being 45% for 15+ years group, and the actual prevalence in lakhs will be 2957.6 (year 2000), 3190.2 (year 2005), 3413.8 (year 2010) and 3624.8 (year 2015). Due to the rampant use of paan masala and ghutka by persons of all age groups and both the sexes, periodontal disease prevalence will be higher than projected. If minor periodontal diseases are included, the proportion of population above the age of 15 years with this disease could be 80% to 90%. Concerned [9] with the urgent need for action, it is vital to promote sound oral health, prevention of dental caries and periodontal diseases and give impetus to activities that promote oral health, WHO had dedicated World Health Day 1994 to oral health. The objectives were to mobilize the dental health resources for promotive action and increase in basic research.

Conclusion

There is a lack of data regarding prevalence of periodontitis among the Indian population. As Doifode [9] observed, "(For) planning of national or regional oral health promotion programs, to prevent and treat oral health problems, baseline data about magnitude of problems and various epidemiological factors is required. Basic oral health surveys provide such type of data. India has vast geographic area divided into states, which differ with regard to their socioeconomic, educational, cultural and behavioral tradition. These factors may affect oral health status. Hence to obtain nationwide representative data, nationwide multicentric study is required. More practicable alternative is to develop regional database; review of such observations from various regions may give understanding of national scenario." There should be a general representative survey of at least all the districts in India to understand the true prevalence of periodontitis. This task is not huge if the responsibility is taken by the 250 odd dental colleges to study their immediate geographical areas. The identification of the disease burden will help to judiciously utilize the limited resources available for periodontal health.

Shah N, Pandey RM, Duggal R, Mathur VP, Rajan K. Oral Health in India: A report of the multi centric study, Directorate General of Health Services, Ministry of Health and Family Welfare, Government of India and World Health Organisation Collaborative Program, December 2007.

Shah N. Oral and dental diseases: Causes, prevention and treatment strategies In NCMH Background Papers-Burden of Disease in India (New Delhi, India). National Commission on Macroeconomics and Health, Ministry of Health and Family Welfare. New Delhi: Government of India; Sep 2005. p. 275-98.